The aim is to accelerate progress in membrane biology, by focussing onto a key area in membrane structural investigations. The proposal focusses specifically on advances in crystallization of membrane proteins for high resolution structure analysis by x-ray crystallography. Successful crystallization of the integral membrane photo-reaction center complex of proteins from R. viridis by Hartmut Michel, and of porin from E. coli membranes by Michael Garavito and colleagues, has led to a moderate resolution x-ray structure determination in about two years, with the certainty of a high resolution structure ahead. These pioneering successes signal the optimum way to determine membrane protein structures, and so to fill a gap in the understanding of membrane biology. The proposal requests support for a workshop like the EMBO workshop in Europe, which would bring Michel, Garavito, and Zulauf from Europe, to teach their methodologies to American investigators who have tried intensively to crystallize integral membrane proteins. The proposal is to place the workshop in an economic and convenient space and time. The University of Colorado in Boulder has offered to provide laboratories, residence, lecture halls and food for attendants. The workshop is modelled after the highly successful EMBO workshop in membrane protein crystallization, and will include lectures by experts in specific areas, and laboratory demonstrations and experiments.